Sorry for posting here in english, pleas need translator

[Cooper1987]

Laivynas, sorry, haven't seen your post

[Esac_mirmidon]

Thanks for your replys but i can´t understand it.

 

It supossed that this table means that you star at diferent speeds, ( 400 to 1300) and diferent alttitudes from 200 to 7000.

 

When you are in ex. 3000 and 600 Km/h pull up at 1 G, all the time 1 G and the measurement of vertical speed in m/sg are the other values in the Y axis.

 

But again i can´t undestand the meaning of this warning.

 

It´s imposible to climb at maximum AoA manteining 1 G.

Also is imposible to climb at 600 Km/h at 1 G if you starts the climb for ex. att 500 like the chart shows.

 

Please someone could help me about this?

 

Thanks for your replys.

[Maximus_G]

I don't see any "1 G" data here at all. This graph is for "Ny = 3", i.e. for 3 Gs.

 

Now let's pay attention to the hatching of the boundary lines. It's at the left side of the "а_доп" line. So "а_доп" limitation would work if, for example, our speed drops _below_ 600 км/ч at h=200м.

 

It means, for example, that when we're moving along the upper curve and cross that "а_доп" line in the direction to the _left_, then our plane woud reach its max_AOA value, and the plane's climb rate would be limited by AOA.

 

And vice versa: if we're constantly increasing our airspeed while maintaining 3 Gs at altitude of 200m (the same topmost curve), then our AOA would drop below its maximum allowed value and decrease further at greater speeds. But our "V_y" ability would be limited by other factors.

 

---

That "а_доп" line is present here because "а_доп" limitation plays very important role in stability of the aircraft. It could be very easy to stall here.

Just as easy it would be to break the plane when we're to the right of the rightmost limiting line.

[Esac_mirmidon]

OK Maximus G.

 

Now i can understand it very well.

 

Sorry for the 1 G explication. This is because the chart is repeated three times for 1 , 3, and 5 G´s and i supposed that the image in the forum was for the 1 G example.

[Bublik]

Vпр usually refers to indicated airspeed, while alpha_доп is the maximum allowable (by RLE) angle of attack, not the critical AoA (it's not the same thing). Maximum allowable AoA for the Su-27 hangs around 20 (depends on Mach number etc), critical is in a neighbourhood of 30.

 

Could you provide some context? As I don't see how the Su-27 can reach alpha_доп at 600 km/h indicated pulling only 3Gs :)

[Esac_mirmidon]

This chart and others about same type are included in the Su27S Manual founded in this link

 

http://www.airwar.ru/fighternow.html

 

If you move down to the botton of the page you can find some resources like this. http://www.airwar.ru/other/bibl/su27mh.html

 

The context of the charts are " Energy for the maneouver and rate of climb Su27 Vs F15 "

 

Also this web contains excelent manuals about Mig29-A. The complete series of manuals including the fliying and navigation manual, combat manual, aerodynamical and technical manual and range, fuel flow and other technical info of the Mig29 A and Mig 29 UB employing de RD33 engines.